Just as a note, it is best to print out your ATT and keep multiple copies in as many places as are feasible. If you keep an electronic copy on your phone, and an officer needs to see your ATT for some reason, do you really want them taking your phone into their cruiser for a few minutes while you have no idea what they're doing to it?
It's a good idea to keep a copy of your ATT and registration certificates inside your transport case, just make sure that's not your only copy.